The Church of Jesus Christ of Latter Day Saints, founded on Joseph Smith's 1830 publication "The Book of Mormon," is the second-fastest growing religion in the world, and its cast album appears to be catching on with similar fervor. The original Broadway cast album of the new musical The Book of Mormon is among the top 10 best-selling albums on iTunes.

The 16-track album was released digitally May 17 by Ghostlight Records and has become the fastest-selling Broadway cast album in iTunes history, according to representatives for the production. By the end of its first day of sales, The Book of Mormon was ranked in the #2 slot and currently stands at #6.

It's a rare occurrence for a Broadway cast album to place among the iTunes best sellers. The cast album for the Green Day musical American Idiot also ranked among the top 10 when it debuted in 2010.

The Book of Mormon has book, music and lyrics by Emmy Award-winning "South Park" creators Trey Parker and Matt Stone, and Avenue Q Tony Award winner Robert Lopez, all of whom earned 2011 Tony Award nominations for Best Original Score and Best Book. The Book of Mormon nabbed a total of 14 Tony Award nominations, including Best Musical.

The hard copy of the album, which will not arrive in stores until June 7, is currently available for purchase at the theatre or pre-order on the Ghostlight Records website, and can be downloaded digitally on iTunes.

Josh Gad ("The Daily Show with Jon Stewart") and Andrew Rannells(Jersey Boys) star as an unlikely pair of Mormon missionaries who venture from Salt Lake City to AIDS-ravaged Uganda in the hopes of converting villagers with the story of Joseph Smith and the founding of the Mormon Church. The problem is: Only one of them has actually read the book.